Display apparatus and method of manufacturing the same

ABSTRACT

A display apparatus including a first non-folding area, a second non-folding area spaced apart from the first non-folding area, and a folding area between the first non-folding area and the second non-folding area, a flexible display panel, a metal plate supporting the flexible display panel and including a recess in the folding area, the metal plate having a first thickness in the first non-folding area and the second non-folding area, and a second thickness less than the first thickness in the folding area, a resin portion disposed in the recess, and a first adhesive layer disposed between the flexible display panel and the metal plate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2019-0124678, filed on Oct. 8, 2019, which isincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Field

Exemplary embodiments of the invention relate generally to a displayapparatus and a method of manufacturing the same and, more specifically,to an in-folding type foldable display apparatus and a method ofmanufacturing the same.

Discussion of the Background

With the development of the technology, display products having smallersizes, lighter weights, and superior performance have been manufactured.Conventional cathode ray tube (CRT) televisions have been widely usedfor display apparatuses due to its performance and price. Recently,however, a display apparatus such as a plasma display apparatus, aliquid crystal display apparatus, and an organic light emitting displayapparatus, which provides various advantages over CRT devices, such asin terms of miniaturization, light weight, and low power consumption,has been spotlighted.

Recently, as bendable and flexible display apparatuses are developed,researches on applying the flexible display apparatus to a mobile devicehaving a foldable structure have been conducted. For example, a foldabledisplay apparatus that includes a folding area and is bendable has beendeveloped. However, when the foldable display apparatus is completelyfolded (e.g., bent angularly) in the folding area, a display elementitself may be damaged. Thus, there are demands for developing a supportstructure having durability while preventing damages by limiting theradius of curvature of the foldable display apparatus that is bent whenthe mobile device is folded. In particular, the quality of the foldabledisplay apparatus may be deteriorated when a wrinkle or a fineconcavo-convex portion in the display area is recognized by the useraccording to the configuration of the support structure.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

Foldable display apparatuses constructed according to exemplaryembodiments of the invention and a manufacturing method of the sameprovide an improved quality.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

A display apparatus including a first non-folding area, a secondnon-folding area spaced apart from the first non-folding area, and afolding area between the first non-folding area and the secondnon-folding area according to an exemplary embodiment includes aflexible display panel, a metal plate supporting the flexible displaypanel and including a recess in the folding area, the metal plate havinga first thickness in the first non-folding area and the secondnon-folding area, and a second thickness less than the first thicknessin the folding area, a resin portion disposed in the recess, and a firstadhesive layer disposed between the flexible display panel and the metalplate.

The metal plate may further include opening patterns in the foldingarea.

The metal plate may include steel use stainless (SUS).

The first thickness of the metal plate may be about 100 μm or less.

The resin portion may include a base and protrusions protruding from thebase and disposed inside the opening patterns, and the protrusions maybe disposed between the base and the flexible display panel.

The resin portion may include a carbon component.

The resin portion may include graphite powder.

The resin portion may have a modulus lower than a modulus of the metalplate.

An air gap may be formed in the opening pattern of the metal plate.

The air gap may be defined by an upper surface of the protrusion of theresin portion and a lower surface of the first adhesive layer.

The first and second non-folding areas may be spaced apart in a firstdirection, and each of the opening patterns of the metal plate mayextend in a second direction perpendicular to the first direction anddisposed in a zigzag form in the first direction.

The opening pattern disposed at an edge of the metal plate in the seconddirection may have one side connected to the edge of the metal plate andis opened, when viewed in a plan view.

The flexible display panel may be configured to be positioned inward ofthe metal plate when the display apparatus is in a folded state due tobending of the folding area.

The display apparatus may further include a cushion layer disposedbetween the first adhesive layer and the flexible display panel, thecushion layer including a foam-shaped material, and a second adhesivelayer disposed between the cushion layer and the flexible display panel.

The flexible display panel may includes a flexible substrate, a thinfilm transistor disposed on the flexible substrate, a first electrodeelectrically connected to the thin film transistor, a light emittingstructure disposed on the first electrode, and a second electrodedisposed on the light emitting structure.

The display apparatus may further include a thin film encapsulationlayer disposed on the second electrode, a third adhesive layer disposedon the thin film encapsulation layer, and a window layer disposed on thethird adhesive layer.

A method of manufacturing a display apparatus including a firstnon-folding area, a second non-folding area spaced apart from the firstnon-folding area, and a folding area between the first non-folding areaand the second non-folding area according to another exemplaryembodiment includes the steps of forming a recess on a metal plate inthe folding area to have a first thickness in the first non-folding areaand the second non-folding area, and a second thickness less than thefirst thickness in the folding area by the recess, forming a resinportion in the recess of the metal plate, attaching a cushion layer ontothe metal plate by using a first adhesive layer, and attaching a displaypanel structure including a flexible display panel onto the cushionlayer.

The step of forming the metal plate may include forming the recess byremoving a portion of the metal plate in the folding area through anetching process, and forming opening patterns on the metal plate in thefolding area through an etching process.

The steps may further include providing a resin solution in the recessand the opening patterns of the metal plate to form a resin portionincluding a base and protrusions protruding from the base and disposedinside the opening patterns.

The step of forming the resin portion may include providing a supportportion having projections corresponding to the opening patterns underthe metal plate before providing the resin solution, and forming theresin portion including the base and the protrusions by providing theresin solution, and when the cushion layer is attached onto the metalplate by using the first adhesive layer, an air gap defined by an uppersurface of the protrusion of the resin portion and a lower surface ofthe first adhesive layer may be formed in the opening pattern.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIG. 1 is a perspective view of a display apparatus according to anexemplary embodiment.

FIG. 2 is a perspective view illustrating a folded state of the displayapparatus of FIG. 1 .

FIG. 3 is a cross-sectional view illustrating a folding area and aportion adjacent thereto of the display apparatus of FIG. 1 .

FIG. 4 is a plan view illustrating a folding area and a portion adjacentthereto of a metal plate of FIG. 3 .

FIG. 5 is a cross-sectional view illustrating a part of a display panelof a display panel structure of the display apparatus of FIG. 3 .

FIG. 6 is a cross-sectional view illustrating a folding area and aportion adjacent thereto of a display apparatus according to anotherexemplary embodiment.

FIGS. 7A, 7B, 7C, 7D, and 7E are cross-sectional views illustrating amethod of manufacturing the display apparatus of FIG. 3 .

FIGS. 8A, 8B, 8C, 8D, and 8E are cross-sectional views illustrating amethod of manufacturing the display apparatus of FIG. 6 .

FIG. 9 is a block diagram illustrating an electronic apparatus accordingto an exemplary embodiment.

FIG. 10 is a perspective view exemplarily illustrating the electronicapparatus of FIG. 9 implemented as a smart phone.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various exemplary embodiments maybe practiced without these specific details or with one or moreequivalent arrangements. In other instances, well-known structures anddevices are shown in block diagram form in order to avoid unnecessarilyobscuring various exemplary embodiments. Further, various exemplaryembodiments may be different, but do not have to be exclusive. Forexample, specific shapes, configurations, and characteristics of anexemplary embodiment may be used or implemented in another exemplaryembodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z-axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference tosectional and/or exploded illustrations that are schematic illustrationsof idealized exemplary embodiments and/or intermediate structures. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should notnecessarily be construed as limited to the particular illustrated shapesof regions, but are to include deviations in shapes that result from,for instance, manufacturing. In this manner, regions illustrated in thedrawings may be schematic in nature and the shapes of these regions maynot reflect actual shapes of regions of a device and, as such, are notnecessarily intended to be limiting.

As is customary in the field, some exemplary embodiments are describedand illustrated in the accompanying drawings in terms of functionalblocks, units, and/or modules. Those skilled in the art will appreciatethat these blocks, units, and/or modules are physically implemented byelectronic (or optical) circuits, such as logic circuits, discretecomponents, microprocessors, hard-wired circuits, memory elements,wiring connections, and the like, which may be formed usingsemiconductor-based fabrication techniques or other manufacturingtechnologies. In the case of the blocks, units, and/or modules beingimplemented by microprocessors or other similar hardware, they may beprogrammed and controlled using software (e.g., microcode) to performvarious functions discussed herein and may optionally be driven byfirmware and/or software. It is also contemplated that each block, unit,and/or module may be implemented by dedicated hardware, or as acombination of dedicated hardware to perform some functions and aprocessor (e.g., one or more programmed microprocessors and associatedcircuitry) to perform other functions. Also, each block, unit, and/ormodule of some exemplary embodiments may be physically separated intotwo or more interacting and discrete blocks, units, and/or moduleswithout departing from the scope of the inventive concepts. Further, theblocks, units, and/or modules of some exemplary embodiments may bephysically combined into more complex blocks, units, and/or moduleswithout departing from the scope of the inventive concepts.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Hereinafter, exemplary embodiments will be described in detail withreference to the accompanying drawings.

FIG. 1 is a perspective view of a display apparatus according to anexemplary embodiment, and FIG. 2 is a perspective view illustrating afolded state of the display apparatus of FIG. 1 .

Referring to FIGS. 1 and 2 , the display apparatus may include a displaypanel structure PNS including a flexible display panel and a supportstructure SPS configured to support the display panel structure PNS.

The display apparatus may include a first non-folding area RA1, a secondnon-folding area RA2 spaced apart from the first non-folding area RA1 ina first direction D1, and a folding area FA disposed between the firstnon-folding area RA1 and the second non-folding area RA2.

The display panel structure PNS may include a display panel (see PN ofFIG. 3 ) configured to display an image, and the image may be displayedon a front surface of the display apparatus. The front surface mayinclude a display area and a non-display area surrounding the displayarea, and the display area may be formed through the first non-foldingarea RA1, the folding area FA, and the second non-folding area RA2.

The display apparatus may be bent to be folded and unfolded by thefolding area FA, and an in-folding type foldable display apparatus maybe implemented, such that the front surfaces configured to displayimages may face each other in the folded state.

FIG. 3 is a cross-sectional view illustrating a folding area and aportion adjacent thereto of the display apparatus of FIG. 1 , and FIG. 4is a plan view illustrating a folding area and a portion adjacentthereto of a metal plate of FIG. 3 .

Referring to FIGS. 1 to 4 , the support structure SPS of the displayapparatus may include a metal plate 100, a resin portion 200, a thirdadhesive layer PSA3, a cushion layer CS, and a second adhesive layerPSA2. The display panel structure PNS of the display apparatus mayinclude a flexible display panel PN, a first adhesive layer PSA1, awindow layer CPI, and a protective layer PL.

The metal plate 100 may support the display panel structure PNS. Themetal plate 100 may include metal. For example, the metal plate 100 mayinclude steel use stainless (SUS). In another exemplary embodiment, themetal plate 100 may include an alloy (for example, a super-elasticmetal), such as nickel-titanium (Ni—Ti), nickel-aluminum (Ni—Al),copper-zinc-nickel (Cu—Zn—Ni), copper-aluminum-nickel (Cu—Al—Ni),copper-aluminum-manganese (Cu—Al—Mn), titanium-nickel-copper-molybdenum(Ti—Ni—Cu—Mo), cobalt-nickel-gallium:iron (Co—Ni—Ga:Fe), silver-nickel(Ag—Ni), gold-cadmium (Au—Cd), iron-platinum (Fe—Pt), iron-nickel(Fe—Ni), and indium-cadmium (In—Cd).

The metal plate 100 may have a first thickness t1 in the firstnon-folding area RA1 and the second non-folding area RA2, and may have asecond thickness t2 less than the first thickness t1 in the folding areaFA, as a recess (e.g., a dented portion) is formed in the folding areaFA. When the metal plate 100 includes SUS, the first thickness t1 may beabout 150 μm and the second thickness t2 may be about 50 μm, withoutbeing limited thereto. In some exemplary embodiments, the firstthickness t1 may be about 100 μm or less.

The recess may be formed on a side opposite to a surface of the metalplate 100 that contacts the second adhesive layer PSA3. The recess maybe substantially filled with the resin portion 200.

Referring to FIG. 4 , opening patterns SL may be formed in the foldingarea FA of the metal plate 100. Each of the opening patterns SL mayextend in the second direction D2. The opening patterns SL may bealternately arranged in the first direction D1, and may extend in thesecond direction D2.

In addition, an edge opening pattern SLE may be disposed at an edge ofthe metal plate 100 in the second direction D2, which may have one sideconnected to the edge of the metal plate 100, thereby having an openedshape when viewed in a plan view.

Although the shape of each of the opening patterns SL has beenillustrated and described as having substantially a rectangular shapewith rounded corners when viewed in a plane view, the inventive conceptsare not limited to one particular shape of the opening patterns SL. Forexample, in some exemplary embodiments, each of the openings may havesubstantially a rectangular planar shape, a triangular planar shape, arhombic planar shape, a polygonal planar shape, a circular planar shape,a track-type planar shape, or an oval planar shape.

The resin portion 200 may be disposed in the recess of the metal plate100. The resin portion 200 may include a base 210 and protrusions 220protruding from the base 210 and disposed inside the opening patternsSL. The protrusions 220 may be disposed between the base 210 and thedisplay panel structure PNS.

The resin portion 200 may include a low modulus material having amodulus lower than a modulus of the metal plate 100. The resin portion200 may include elastomer having a relatively large elastic force orrelatively large restoring force. For example, the resin portion 200 mayinclude an elastic material, such as silicone, urethane, andthermoplastic polyurethane (TPU). In another exemplary embodiment, theresin portion 200 may include polyethylene terephthalate (PET),polyethylene naphthalene (PEN), polypropylene (PP), polycarbonate (PC),polystyrene (PS), polysulfone (PSul), polyethylene (PE), polyphthalamide(PPA), polyethersulfone (PES), polyarylate (PAR), polycarbonate oxide(PCO), modified polyphenylene oxide (MPPO), and the like.

The resin portion 200 may prevent damages from repeated folding andunfolding by supporting a part of the folding area FA of the metal plate100 that is relatively thin. In addition, while the display apparatusrepeatedly performs folding and unfolding, the resin portion 200 mayprevent foreign matters from permeating into the opening patterns SL.Furthermore, while the display apparatus repeatedly performs folding andunfolding, the resin portion 200 may be stretched and shrunk to preventthe opening patterns SL from being exposed.

The resin portion 200 may include a carbon component having excellentthermal conductivity, so that the excellent thermal conductivityproperties may be provided. The carbon component may include graphene,carbon nanotubes, graphite, and the like. For example, the resin portion200 may include graphite powder.

The third adhesive layer PSA3 may be disposed on the metal plate 100.The third adhesive layer PSA3 may be bonded to parts of the metal plate100 and the resin portion 200. The third adhesive layer PSA3 may includean optical clear adhesive (OCA), a pressure sensitive adhesive (PSA),photo-curable resin or thermosetting resin, and the like. For example,the adhesive may include PET, PEN, PP, PC, PS, PSul, PE, PPA, PES, PAR,PCO, MPPO, and the like, and the resin may include epoxy resin, aminoresin, phenol resin, urea resin, melamine resin, unsaturated polyesterresin, polyurethane resin, polyimide resin, and the like.

The cushion layer CS may be disposed on the third adhesive layer PSA3.The cushion layer CS may include a material having ductility, so thatthe display panel structure PNS may be easily folded. For example, thecushion layer CS may include a foam-type material, such as apolyurethane foam and a polystyrene foam.

The second adhesive layer PSA2 may be disposed on the cushion layer CS.The display panel structure PNS may be bonded to the second adhesivelayer PSA2. The second adhesive layer PSA2 may include an optical clearadhesive (OCA), a pressure sensitive adhesive (PSA), photo-curable resinor thermosetting resin, and the like. For example, the adhesive mayinclude PET, PEN, PP, PC, PS, PSul, PE, PPA, PES, PAR, PCO, MPPO, andthe like, and the resin may include epoxy resin, amino resin, phenolresin, urea resin, melamine resin, unsaturated polyester resin,polyurethane resin, polyimide resin, and the like.

When the folding area FA of the metal plate 100 formed of a metalmaterial is repeatedly folded and unfolded, a temperature at the portionformed with the opening patterns SL in the folding area FA of the metalplate 100 may be increased, which may increase stress to therebygenerate cracks. According to the illustrated exemplary embodiment, themetal plate 100 is formed of metal, so that heat in the display panelstructure PNS may be efficiently discharged. In addition, the foldingarea FA of the metal plate 100 may be thinner than other portions andmay be formed with the opening patterns SL, so that the bendability maybe improved. Further, the resin portion 200 may be formed of a resinmaterial including carbon components having excellent thermalconductivity properties and low modulus, so that heat may be dissipated,the flatness on an outer surface may be improved, and the vibrationnoise during folding the display apparatus may be reduced in the foldingarea FA.

The flexible display panel PN may be disposed on the second adhesivelayer PSA2. The flexible display panel PN may be a flexible organiclight emitting display panel, which will be described in more detaillater with reference to FIG. 5 .

The first adhesive layer PSA1 may be disposed on the flexible displaypanel PN. The first adhesive layer PSA1 may include an optical clearadhesive (OCA), a pressure sensitive adhesive (PSA), photo-curable resinor thermosetting resin, and the like. For example, the adhesive mayinclude PET, PEN, PP, PC, PS, PSul, PE, PPA, PES, PAR, PCO, MPPO, andthe like, and the resin may include epoxy resin, amino resin, phenolresin, urea resin, melamine resin, unsaturated polyester resin,polyurethane resin, polyimide resin, and the like.

The window layer CPI may be disposed on the first adhesive layer PSA1.The window layer CPI may be a transparent flexible film, such asultra-thin glass or transparent polyimide.

The protective layer PL may be disposed on the window layer CPI andprotect the window layer CPI. The protective layer PL may be bonded tothe window layer CPI by an adhesive layer to facilitate replacement ofthe protective layer PL as needed.

FIG. 5 is a cross-sectional view illustrating a part of a display panelof a display panel structure of the display apparatus of FIG. 3 .

Referring to FIGS. 3 and 5 , the display panel PN may include a flexiblesubstrate 300, a thin film transistor TFT, a first insulating layer 310,a second insulating layer 320, a via insulating layer VIA, a pixeldefining layer PDL, a light emitting structure 380, a thin filmencapsulation Layer TFE, and the like. The thin film transistor TFT mayinclude an active pattern ACT, a gate electrode GE, a source electrodeSE, and a drain electrode DE. The light emitting structure 380 mayinclude a first electrode 381, a light emitting layer 382, and a secondelectrode 383.

The flexible substrate 300 may include a transparent or opaque material.The flexible substrate 300 may be disposed on the second adhesive layerPSA2. The flexible substrate 300 may be formed of a transparent resinsubstrate, such as a polyimide substrate. In this case, the polyimidesubstrate may include a first polyimide layer, a barrier film layer, asecond polyimide layer, and the like. In some exemplary embodiments, theflexible substrate 300 may include a quartz substrate, a syntheticquartz substrate, a calcium fluoride substrate, a fluorine-doped(F-doped) quartz substrate, a soda-lime glass substrate, a non-alkaliglass substrate, and the like.

A buffer layer may be disposed on the flexible substrate 300. The bufferlayer may prevent metal atoms or impurities from diffusing into the thinfilm transistor TFT from the flexible substrate 300. The buffer layermay also allow the active pattern ACT to have a substantial uniformityby adjusting the heat transfer rate during crystallization process forforming the active pattern ACT. In addition, when a surface of theflexible substrate 300 is not uniform, the buffer layer may improve theflatness of the surface of the flexible substrate 300. Depending on atype of flexible substrate 300, two or more buffer layers may beprovided on the flexible substrate 300 or the buffer layer may beomitted. For example, the buffer layer may include an organic materialor an inorganic material.

The active pattern ACT may be disposed on the flexible substrate 300.The active pattern ACT may include a metal oxide semiconductor, aninorganic semiconductor, such as amorphous silicon and poly silicon, anorganic semiconductor, and the like. The active pattern ACT may have asource area, a drain area, and a channel area between the source areaand the drain area.

The first insulating layer 310 may be disposed on the active patternACT. For example, the first insulating layer 310 may sufficiently coverthe active pattern ACT on the flexible substrate 300, and may have asubstantially planar upper surface without generating a step around theactive pattern ACT. In some exemplary embodiments, the first insulatinglayer 310 may be disposed to have a uniform thickness along the profileof the active pattern ACT while covering the active pattern ACT on theflexible substrate 300. The first insulating layer 310 may include asilicon compound, metal oxide, and the like. For example, the firstinsulating layer 310 may include silicon oxide (SiO_(x)), siliconnitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y)), silicon oxycarbide(SiO_(x)C_(y)), silicon carbonitride (SiC_(x)N_(y)), aluminum oxide(AlO_(x)), aluminum nitride (AlN_(x)), tantalum oxide (TaO_(x)), hafniumoxide (HfO_(x)), zirconium oxide (ZrO_(x)), titanium oxide (TiO_(x)),and the like. In some exemplary embodiments, the first insulating layer310 may have a multi-layer structure including a plurality of insulatinglayers. For example, the insulating layers may have mutually differentthicknesses or include mutually different materials.

A gate pattern including a gate electrode GE may be disposed on thefirst insulating layer 310. The gate pattern may be disposed to overlapthe channel area of the active pattern ACT. The gate electrode GE mayinclude metal, an alloy, a metal nitride, a conductive metal oxide, atransparent conductive material, and the like. For example, the gateelectrode GE may include gold (Au), silver (Ag), aluminum (Al), tungsten(W), copper (Cu), platinum (Pt), nickel (Ni), titanium (Ti), palladium(Pd), magnesium (Mg), calcium (Ca), lithium (Li), chromium (Cr),tantalum (Ta), molybdenum (Mo), scandium (Sc), neodymium (Nd), iridium(Ir), an alloy containing aluminum, aluminum nitride (AlN_(x)), an alloycontaining silver, tungsten nitride (WN_(x)) an alloy containing copper,an alloy containing molybdenum, titanium nitride (TiN_(x)), chromiumnitride (CrN_(x)), tantalum nitride (TaN_(x)), strontium ruthenium oxide(SrRu_(x)O_(y)), zinc oxide (ZnO_(x)), indium tin oxide (ITO), tin oxide(SnO_(x)), indium oxide (InO_(x)), gallium oxide (GaO_(x)), indium zincoxide (IZO), and the like. These may be used individually or incombination. In some exemplary embodiments, the gate pattern may includea multi-layer structure including a plurality of metal layers. Forexample, the metal layers may have mutually different thicknesses orinclude mutually different materials.

The second insulating layer 320 may be disposed on the gate pattern. Forexample, the second insulating layer 320 may sufficiently cover the gatepattern on the first insulating layer 310, and may have a substantiallyplanar upper surface without generating a step around the gate pattern.In some exemplary embodiments, the second insulating layer 320 may bedisposed to have a uniform thickness along a profile of the gate patternwhile covering the gate pattern on the first insulating layer 310. Thesecond insulating layer 320 may include a silicon compound, metal oxide,and the like. In some exemplary embodiments, the second insulating layer320 may have a multi-layer structure including a plurality of insulatinglayers. For example, the insulating layers may have mutually differentthicknesses or include mutually different materials.

A data pattern including a source electrode SE and a drain electrode DEof the thin film transistor TFT may be disposed on the second insulatinglayer 320. The source electrode SE may be connected to the source areaof the active pattern ACT through a contact hole formed by removingfirst portions of the first insulating layer 310 and the secondinsulating layer 320, and the drain electrode DE may be connected to thedrain area of the active pattern ACT through a contact hole formed byremoving second portions of the first insulating layer 310 and thesecond insulating layer 320. The data pattern may include metal, analloy, a metal nitride, a conductive metal oxide, a transparentconductive material, and the like. These may be used individually or incombination. In some exemplary embodiments, the data pattern may have amulti-layer structure including a plurality of metal layers. Forexample, the metal layers may have mutually different thicknesses orinclude mutually different materials.

Accordingly, the thin film transistor TFT, which includes the activepattern ACT, the first insulating layer 310, the gate electrode 170, thesecond insulating layer 320, the source electrode SE, and the drainelectrode DE, may be formed.

Although the thin film transistor TFT has been shown and described ashaving a top gate structure, the inventive concepts are not limitedthereto. For example, in some exemplary embodiments, the thin filmtransistor TFT may have a bottom gate structure, a double gatestructure, or the like.

The via-insulating layer VIA may be disposed on the second insulatinglayer 320 and the data pattern. For example, the via-insulating layerVIA may be disposed to have a relatively thick thickness. In this case,the via-insulating layer VIA may have a substantially planar uppersurface. In order to from the planar upper surface of the via-insulatinglayer VIA, a planarization process may be performed on thevia-insulating layer VIA. In some exemplary embodiments, thevia-insulating layer VIA may be disposed to have a uniform thicknessalong a profile of the data pattern on the second insulating layer 320.The via-insulating layer VIA may be formed of an organic material or aninorganic material. In some exemplary embodiments, the via-insulatinglayer VIA may include an organic material. For example, thevia-insulating layer VIA may include photoresist, polyacryl-based resin,polyimide-based resin, polyamide-based resin, siloxane-based resin,acryl-based resin, epoxy-based resin, and the like.

The first electrode 381 may be disposed on the via-insulating layer VIA.The first electrode 381 may be electrically connected to the thin filmtransistor TFT through a contact hole formed by removing a part of thevia-insulating layer VIA. The first electrode 381 may include metal, analloy, a metal nitride, a conductive metal oxide, a transparentconductive material, and the like. These may be used individually or incombination. In some exemplary embodiments, the first electrode 381 mayhave a multi-layer structure including a plurality of metal layers. Forexample, the metal layers may have mutually different thicknesses orinclude mutually different materials.

The pixel defining layer PDL may be disposed on the via-insulating layerVIA. For example, the pixel defining layer PDL may expose a part of theupper surface of the first electrode 381 while covering both sideportions of the first electrode 381. The pixel defining layer PDL may beformed of an organic material or an inorganic material. In someexemplary embodiments, the pixel defining layer PDL may include anorganic material.

The light emitting layer 382 may be disposed on the pixel defining layerPDL and the first electrode 381. The light emitting layer 382 mayinclude at least one of light emitting materials capable of emittingcolor lights, such as red light, green light, and blue light, that aredifferent according to sub-pixels. In some exemplary embodiments, thelight emitting layer 382 may be formed by laminating a plurality oflight emitting materials capable of generating different color light,such as red light, green light, and blue light, such that white lightmay be emitted as a whole. In this case, a color filter may be disposedon the light emitting layer 382 disposed on the first electrode 381. Thecolor filter may include at least one of a red color filter, a greencolor filter, and a blue color filter. In some exemplary embodiments,the color filter may include a yellow color filter, a cyan color filter,and a magenta color filter. The color filter may include photosensitiveresin or color photoresist.

The second electrode 383 may be disposed on the light emitting layer 382and the pixel defining layer PDL. The second electrode 383 may includemetal, an alloy, a metal nitride, a conductive metal oxide, atransparent conductive material, and the like. These may be usedindividually or in combination. In some exemplary embodiments, thesecond electrode 383 may have a multi-layer structure including aplurality of layers. For example, the metal layers may have mutuallydifferent thicknesses or include mutually different materials.

The thin film encapsulation layer TFE may be disposed on the secondelectrode 383. The thin film encapsulation layer TFE may include atleast one inorganic layer and organic layer that are alternatelylaminated. For example, the thin film encapsulation layer TFE mayinclude a first inorganic layer, an organic layer on the first inorganiclayer, and a second inorganic layer disposed on the organic layer. Thethin film encapsulation layer TFE may prevent the light emitting layer382 from being deteriorated due to permeation of the moisture, oxygen,or the like. In addition, the thin film encapsulation layer TFE may alsoprotect the display panel PN from an external impact. In addition, thethin film encapsulation layer TFE may improve the flatness of thedisplay panel PN.

In the illustrated exemplary embodiment, although the display apparatushas been described as including an organic light emitting display panel,the inventive concepts are not limited thereto. In some exemplaryembodiments, the display apparatus may include a liquid crystal displayapparatus (LCD), a field emission display (FED), a plasma display panel(PDP), or an electrophoretic display apparatus (EPD).

FIG. 6 is a cross-sectional diagram illustrating a folding area and aportion adjacent thereto of a display apparatus according to anotherexemplary embodiment.

Referring to FIG. 6 , the display apparatus is substantially the same asthe display apparatus of FIG. 3 , except that an air gap AG is formed inthe opening pattern of the metal plate 100. Accordingly, repeateddescriptions of the substantially the same elements of the displayapparatus already described above will be omitted.

The display apparatus according to the illustrated exemplary embodimentmay include a display panel structure PNS including a flexible displaypanel, and a support structure SPS configured to support the displaypanel structure PNS.

The support structure SPS of the display apparatus may include a metalplate 100, a resin portion 200, a third adhesive layer PSA3, a cushionlayer CS, and a second adhesive layer PSA2. The display panel structurePNS of the display apparatus may include a flexible display panel PN, afirst adhesive layer PSA1, a window layer CPI, and a protective layerPL.

An air gap AG may be formed in the opening pattern of the metal plate100. The air gap AG may be defined by an upper surface of the protrusion220 of the resin portion 200 and a lower surface of the third adhesivelayer PSA3.

When the folding area FA of the display apparatus is bent, a part of theresin portion 200 may be pushed up or down with respect to the openingpattern of the metal plate 100. In this case, a pressure may be appliedin a direction of flexible display panel PN or in an opposite direction,which may form a concavo-convex portion on the display surface. In thedisplay apparatus according to the illustrated exemplary embodiment,however, since the air gap AG is formed in the opening pattern of themetal plate 100, the generation of a concavo-convex portion on thedisplay surface may be prevented or at least be suppressed when thefolding area FA of the display apparatus is bent.

Accordingly, the quality of the display surface of the display apparatusmay be improved, and the wrinkles and the like in the folding area FAmay be prevented or at least be suppressed.

In addition, since the air gap AG is formed without filling the openingpattern of the metal plate 100 with the protrusions 220 of the resinportion 200, an adhesive strength between the upper surface of the metalplate 100 and the third adhesive layer PSA3 in the folding area FA maybe increased due to the air gap AG.

FIGS. 7A to 7E are cross-sectional view illustrating a method ofmanufacturing the display apparatus of FIG. 3 .

Referring to FIG. 7A, a primary etching process may be performed on themetal plate 100 to remove a portion of the metal plate 100 thatcorresponds to the folding area FA. For example, a photoresist layer maybe formed on the metal plate 100, and the photoresist layer may beexposed and developed, so that a photoresist pattern covering the firstnon-folding area RA1 and the second non-folding area RA2 may be formed.Then, the metal plate 100 may be etched by using the photoresist patternas an etching barrier, so that the metal plate 100 may be formed to havea first thickness t1 in the first non-folding area RA1 and the secondnon-folding area RA2, and have a second thickness t2 less than the firstthickness t1 in the folding area FA.

Referring to FIG. 7B, an opening pattern SL may be formed in the foldingarea FA of the metal plate 100 by a secondary etching process. Forexample, a photoresist layer may be formed on the metal plate 100, andthe photoresist layer may be exposed and developed, so that aphotoresist pattern may cover parts of the first non-folding area RA1,the second non-folding area RA2, and the folding area FA. Then, themetal plate 100 may be etched by using the photoresist pattern as anetch barrier so that the opening pattern SL may be formed.

Although the primary etching process and the secondary etching processhave been described as being performed through separate processes, insome exemplary embodiments, the portion having the first thickness t1and the opening pattern SL may be formed through one etching processusing a halftone mask or the like.

Referring to FIG. 7C, the resin portion 200 may be formed on the metalplate 100. The resin portion 200 may be formed in the recess, which is aportion removed through the primary and secondary etching processes, ofthe folding area FA of the metal plate 100. For example, a resinsolution may be injected and cured to form the resin portion 200including the base 210 and the protrusion 220 that are disposed in theopening pattern SL of the metal plate 100.

Referring to FIG. 7D, a third adhesive layer PSA3, a cushion layer CS,and a second adhesive layer PSA2 may be formed on the metal plate 100.For example, after the third adhesive layer PSA3 and the second adhesivelayer PSA2 are attached onto both sides of the cushion layer CS,respectively, the third adhesive layer PSA3 is attached onto a surfaceof the metal plate 100 that opposes the base 210 of the resin portion200. In this manner, the support structure SPS may be formed.

Referring to FIG. 7E, the display panel structure PNS may be attachedonto the second adhesive layer PSA2 of the support structure SPS, sothat the display apparatus may be manufactured.

The display panel structure PNS may include a display panel PN, a firstadhesive layer PSA1 disposed on the display panel PN, a window layer CPIdisposed on the first adhesive layer PSA1, and a protective layer PLdisposed on the window layer CPI. For example, the display panelstructure PNS may be formed by attaching the window layer CPI and theprotective layer PL onto the display panel PN, which may be a flexibleorganic light emitting display panel, by using the first adhesive layerPSA1.

FIGS. 8A to 8D are cross-sectional views illustrating a method ofmanufacturing the display apparatus of FIG. 6 . The manufacturing methodaccording to the illustrated exemplary embodiment is substantially thesame as the method described above with reference to FIGS. 7A to 7E,except for forming an air gap AG. As such, repeated descriptions ofsubstantially the same steps described above will be omitted.

Referring to FIG. 8A, a portion corresponding to the folding area FA ofthe metal plate 100 may be partially removed, so that the metal plate100 may be formed to have a first thickness t1 in the first non-foldingarea RA1 and the second non-folding area RA2, and have a secondthickness t2 less than the first thickness t1 in the folding area FA.

Referring to FIG. 8B, an opening pattern SL may be formed in the foldingarea FA of the metal plate 100.

Referring to FIG. 8C, the resin portion 200 may be formed on the metalplate 100. A support portion 10 may be disposed below the metal plate100, and projections 12 may be formed in the support portion 10 tocorrespond to the opening pattern SL of the metal plate. In this case,the resin solution for forming the resin portion 200 may not be filledin the projections 12. Accordingly, an end of each protrusion 220 of theresin portion 200 may have a dented shape. The dented shape may providea space for forming an air gap AG to be described later.

Referring to FIG. 8D, the support portion 10 may be removed from themetal plate 100, and a third adhesive layer PSA3, a cushion layer CS,and a second adhesive layer PSA2 may be formed on the metal plate 100.For example, after the third adhesive layer PSA3 and the second adhesivelayer PSA2 are attached onto both sides of the cushion layer CS,respectively, the third adhesive layer PSA3 is attached onto a surfaceof the metal plate 100 that opposes the base 210 of the resin portion200. In this manner, the support structure SPS may be formed.

Since the dented shape is formed at the end of the protrusion 220 of theresin portion 200, the air gap AG may be formed between the lowersurface of the third adhesive layer PSA3 and the upper surface of theprotrusion 220.

Referring to FIG. 8E, the display panel structure PNS may be attachedonto the second adhesive layer PSA2 of the support structure SPS, sothat the display apparatus may be manufactured.

The display panel structure PNS may include a display panel PN, a firstadhesive layer PSA1 disposed on the display panel PN, a window layer CPIdisposed on the first adhesive layer PSA1, and a protective layer PLdisposed on the window layer CPI.

FIG. 9 is a block diagram illustrating an electronic apparatus accordingto an exemplary embodiment, and FIG. 10 is a perspective view ofexemplarily illustrating an electronic apparatus of FIG. 9 implementedas a smart phone.

Referring to FIGS. 9 and 10 , the electronic apparatus 500 may include aprocessor 510, a memory device 520, a storage device 530, aninput/output (I/O) device 540, a power supply 550, and a displayapparatus 560. The display apparatus 560 may include the displayapparatus of FIG. 1 . In addition, the electronic apparatus 500 mayfurther include a plurality of ports for communicating with a videocard, a sound card, a memory card, a universal serial bus (USB) device,other electronic apparatuses, etc. In an exemplary embodiment, asillustrated in FIG. 10 , the electronic apparatus 500 may be implementedas a foldable smart phone. However, the electronic apparatus 500 is notlimited thereto. For example, the electronic apparatus 500 may beimplemented as a cellular phone, a video phone, a smart pad, a smartwatch, a tablet PC, a car navigation system, a computer monitor, alaptop, a head mounted display (HMD) apparatus, etc.

The processor 510 may perform various computing functions. The processor510 may be a micro processor, a central processing unit (CPU), anapplication processor (AP), etc. The processor 510 may be coupled toother components via an address bus, a control bus, a data bus, etc.Further, the processor 510 may be coupled to an extended bus, such as aperipheral component interconnection (PCI) bus. The memory device 520may store data for operations of the electronic apparatus 500. Forexample, the memory device 520 may include at least one non-volatilememory device, such as an erasable programmable read-only memory (EPROM)device, an electrically erasable programmable read-only memory (EEPROM)device, a flash memory device, a phase change random access memory(PRAM) device, a resistance random access memory (RRAM) device, a nanofloating gate memory (NFGM) device, a polymer random access memory(PoRAM) device, a magnetic random access memory (MRAM) device, aferroelectric random access memory (FRAM) device, etc., and/or at leastone volatile memory device, such as a dynamic random access memory(DRAM) device, a static random access memory (SRAM) device, a mobileDRAM device, etc. The storage device 530 may include a solid state drive(SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. TheI/O device 540 may include an input device, such as a keyboard, akeypad, a mouse device, a touch-pad, a touch-screen, etc., and an outputdevice, such as a printer, a speaker, etc. The power supply 550 mayprovide power for operations of the electronic apparatus 500.

The display apparatus 560 may be coupled to other components via thebuses or other communication links. In some exemplary embodiments, theI/O device 540 may include the display apparatus 560. As describedabove, the display apparatus 560 may include a first non-folding area, asecond non-folding area spaced apart from the first non-folding area,and a folding area between the first non-folding area and the secondnon-folding area. The display apparatus may include a flexible displaypanel, a metal plate configured to support the flexible display paneland having a first thickness in the first non-folding area and thesecond non-folding area and a second thickness less than the firstthickness in the folding area due to a recess formed in the foldingarea, a resin portion disposed in the recess, and a first adhesive layerdisposed between the flexible display panel and the metal plate. Themetal plate may be formed of metal, so that the heat of the flexibledisplay panel may be efficiently discharged (or emitted). In addition,the folding area of the metal plate may be formed thinner than otherportions, and opening patterns may be formed in the folding area, sothat the bendability may be improved. Further, the resin portion may beformed of a resin material including carbon components having excellentthermal conductivity properties and having a low modulus, so that theheat may be dissipated, the flatness on an outer surface may beimproved, and the vibration noise from folding the display apparatus maybe reduced, in the folding area.

The exemplary embodiments may be applied to a display apparatus (e.g.,an organic light-emitting display apparatus) and an electronic apparatusincluding the display apparatus. For example, the exemplary embodimentsmay be applied to a smart phone, a cellular phone, a video phone, asmart pad, a smart watch, a tablet PC, a car navigation system, atelevision, a computer monitor, a laptop, a head mounted displayapparatus, etc.

According to exemplary embodiments, a display apparatus may include afirst non-folding area, a second non-folding area spaced apart from thefirst non-folding area, and a folding area between the first non-foldingarea and the second non-folding area. The display apparatus may includea flexible display panel, a metal plate configured to support theflexible display panel and having a first thickness in the firstnon-folding area and the second non-folding area and a second thicknessless than the first thickness in the folding area due to a recess formedin the folding area, a resin portion disposed in the recess, and a firstadhesive layer disposed between the flexible display panel and the metalplate. The metal plate may be formed of metal, so that heat of theflexible display panel may be efficiently discharged (or emitted). Inaddition, the folding area of the metal plate may be formed thinner thanother portions, and opening patterns may be formed, so that thebendability may be improved. Further, the resin portion may be formed ofa resin material including carbon components having excellent thermalconductivity properties and having a low modulus, so that the heat maybe dissipated, the flatness on an outer surface may be improved, and thevibration noise due to folding may be reduced, in the folding area.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of theappended claims and various obvious modifications and equivalentarrangements as would be apparent to a person of ordinary skill in theart.

What is claimed is:
 1. A display apparatus including a first non-foldingarea, a second non-folding area spaced apart from the first non-foldingarea, and a folding area between the first non-folding area and thesecond non-folding area, the display apparatus comprising: a flexibledisplay panel having a display area disposed in the first non-foldingarea, the second non-folding area, and the folding area; a metal platesupporting the flexible display panel and including a recess in thefolding area, the metal plate having a first thickness in the firstnon-folding area and the second non-folding area, and a second thicknessless than the first thickness in the folding area; a resin portiondisposed in the recess; and a first adhesive layer disposed between theflexible display panel and the metal plate.
 2. The display apparatus ofclaim 1, wherein the metal plate further includes opening patterns inthe folding area, and wherein the recess overlaps the display area ofthe flexible display panel in a plan view.
 3. The display apparatus ofclaim 2, wherein the metal plate includes steel use stainless (SUS). 4.The display apparatus of claim 3, wherein the first thickness of themetal plate is about 100 μm or less.
 5. The display apparatus of claim2, wherein: the resin portion includes a base and protrusions protrudingfrom the base and disposed inside the opening patterns; and theprotrusions are disposed between the base and the flexible displaypanel.
 6. The display apparatus of claim 5, wherein the resin portionincludes a carbon component.
 7. The display apparatus of claim 6,wherein the resin portion includes graphite powder.
 8. The displayapparatus of claim 5, wherein the resin portion has a modulus lower thana modulus of the metal plate.
 9. The display apparatus of claim 5,wherein an air gap is formed in the opening pattern of the metal plate.10. The display apparatus of claim 9, wherein the air gap is defined byan upper surface of the protrusion of the resin portion and a lowersurface of the first adhesive layer.
 11. The display apparatus of claim2, wherein: the first and second non-folding areas are spaced apart in afirst direction; and each of the opening patterns of the metal plateextends in a second direction perpendicular to the first direction andis disposed in a zigzag form in the first direction.
 12. The displayapparatus of claim 11, wherein the opening pattern disposed at an edgeof the metal plate in the second direction has one side connected to theedge of the metal plate and is opened, when viewed in a plan view. 13.The display apparatus of claim 1, wherein the flexible display panel isconfigured to be positioned inward of the metal plate when the displayapparatus is in a folded state due to bending of the folding area. 14.The display apparatus of claim 1, further comprising: a cushion layerdisposed between the first adhesive layer and the flexible displaypanel, the cushion layer including a foam-shaped material; and a secondadhesive layer disposed between the cushion layer and the flexibledisplay panel.
 15. The display apparatus of claim 1, wherein theflexible display panel includes: a flexible substrate; a thin filmtransistor disposed on the flexible substrate; a first electrodeelectrically connected to the thin film transistor; a light emittingstructure disposed on the first electrode; and a second electrodedisposed on the light emitting structure.
 16. The display apparatus ofclaim 15, further comprising: a thin film encapsulation layer disposedon the second electrode; a third adhesive layer disposed on the thinfilm encapsulation layer; and a window layer disposed on the thirdadhesive layer.
 17. A method of manufacturing a display apparatusincluding a first non-folding area, a second non-folding area spacedapart from the first non-folding area, and a folding area between thefirst non-folding area and the second non-folding area, the methodcomprising: forming a recess on a metal plate in the folding area tohave a first thickness in the first non-folding area and the secondnon-folding area, and a second thickness less than the first thicknessin the folding area by the recess; forming a resin portion in the recessof the metal plate; attaching a cushion layer onto the side of the metalplate opposite to the resin portion by using a first adhesive layer; andattaching a display panel structure including a flexible display panelonto the cushion layer, wherein the flexible display panel has a displayarea disposed in the first non-folding area, the second non-foldingarea, and the folding area.
 18. The method of claim 17, wherein formingthe metal plate includes: forming the recess by removing a portion ofthe metal plate in the folding area through an etching process; andforming opening patterns on the metal plate in the folding area throughan etching process, and wherein the recess overlaps the display area ofthe flexible display panel in a plan view.
 19. The method of claim 18,further comprising providing a resin solution in the recess and theopening patterns of the metal plate to form a resin portion including abase and protrusions protruding from the base and disposed inside theopening patterns.
 20. The method of claim 19, wherein forming the resinportion includes: providing a support portion having projectionscorresponding to the opening patterns under the metal plate beforeproviding the resin solution; and forming the resin portion includingthe base and the protrusions by providing the resin solution, andremoving the support portion from the metal plate, and wherein, when thecushion layer is attached onto the metal plate by using the firstadhesive layer, an air gap defined by an upper surface of the protrusionof the resin portion and a lower surface of the first adhesive layer isformed in the opening pattern.